Attention is directed to co-pending application Ser. No. 457,586, filed Apr. 3, 1974, and U.S. Pat. No. 3,885,409 dated May 27, 1975.
Continuing attempts are being made to try to produce pin tumbler locks that are actually pick proof. Much has been done in this matter and the above-mentioned patent and pending application are referred to in this connection. However, it is found that the pins in pin tumbler locks may be picked in some cases or may be sheared by a strong tool inserted into a keyway. It is the general object of the present invention to provide a pin tumbler lock which is extremely difficult to be picked and which is exceptionally strong.